Hibernation in golden hamsters (Mesocricetus auratus, W.) exposed to 5% CO2

Kuhnen, Gernot; Petersen, P.; Wünnenberg, W.

doi:10.1007/bf01990095

Cited by 8 publications

(2 citation statements)

References 5 publications

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“…Several studies suggested that hypercapnia and hypoxia may induce or facilitate entry into torpor by suppressing metabolism (Studier and Baca, 1968;Williams and Rausch, 1973;Schäfer and Wünnenberg, 1976;Kuhnen et al, 1983). But there are also contrary observations described in the literature.…”

Section: Preparation For Entrance Into Torpormentioning

confidence: 96%

Cardiorespiratory and metabolic reactions during entrance into torpor in dormice, Glis glis

Elvert¹,

Heldmaier

2005

Journal of Experimental Biology

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Dormice voluntarily enter torpor at ambient temperatures ranging between 0-28°C. This study describes heart rate, ventilation frequency, O 2 -consumption (defined as metabolic rate), CO 2 -production and body temperature during entrance into torpor. Their temporal relationship was analysed during the time course of metabolic depression at different ambient temperatures. Body temperature and heart rate were measured in unrestrained dormice with implanted transmitter. Ventilation frequency was monitored by total body plethysmography or infrared video monitoring. To compare entries into torpor at different T a these periods were distinguished into four different phases: the resting phase prior to torpor, the phase of pre-torpor adjustments, the reduction phase and the phase of steady state torpor. In the pre-torpor phase, dormice increased their ventilation, metabolic rate and heart rate, indicating that the torpid state is initiated by an enhanced metabolic activity for about an hour. This was followed by a rapid reduction of ventilation, metabolism and heart rate, which reached their minimum values long before body temperature completed its decline. The results of the present study show that the entrance into torpor is caused by an active respiratory, cardiac and metabolic depression.

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Section: Preparation For Entrance Into Torpormentioning

confidence: 96%

Cardiorespiratory and metabolic reactions during entrance into torpor in dormice, Glis glis

Elvert¹,

Heldmaier

2005

Journal of Experimental Biology

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“…For instance, respiratory acidosis in an euthermic hamster induced by breathing 10% CO2 results in depression of hypothalamic neuronal activity involved in thermoregulation (Wiinnenberg and Baltruschat 1982). This could facilitate the lowering of Tset and entry into hibernation as has been demonstrated in hamsters under 5% CO2 , 21 % O 2 , and 74% N 2 (Kuhnen et al 1983). Further, glycolysis is severely depressed by acidosis due to the inhibition of phosphofructokinase by low pH, which dissociates the catalytically -120 Torr Fig.…”

Section: Respiratory Functionsmentioning

confidence: 89%

Mammalian Hibernation: An Escape from the Cold

Wang

1988

Advances in Comparative and Environmental Physiology

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Hibernation and Gas Exchange

Milsom

Jackson

2011

Comprehensive Physiology

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Hibernation in endotherms and ectotherms is characterized by an energy-conserving metabolic depression due to low body temperatures and poorly understood temperature-independent mechanisms. Rates of gas exchange are correspondly reduced. In hibernating mammals, ventilation falls even more than metabolic rate leading to a relative respiratory acidosis that may contribute to metabolic depression. Breathing in some mammals becomes episodic and in some small mammals significant apneic gas exchange may occur by passive diffusion via airways or skin. In ectothermic vertebrates, extrapulmonary gas exchange predominates and in reptiles and amphibians hibernating underwater accounts for all gas exchange. In aerated water diffusive exchange permits amphibians and many species of turtles to remain fully aerobic, but hypoxic conditions can challenge many of these animals. Oxygen uptake into blood in both endotherms and ectotherms is enhanced by increased affinity of hemoglobin for O₂ at low temperature. Regulation of gas exchange in hibernating mammals is predominately linked to CO₂/pH, and in episodic breathers, control is principally directed at the duration of the apneic period. Control in submerged hibernating ectotherms is poorly understood, although skin-diffusing capacity may increase under hypoxic conditions. In aerated water blood pH of frogs and turtles either adheres to alphastat regulation (pH ∼8.0) or may even exhibit respiratory alkalosis. Arousal in hibernating mammals leads to restoration of euthermic temperature, metabolic rate, and gas exchange and occurs periodically even as ambient temperatures remain low, whereas body temperature, metabolic rate, and gas exchange of hibernating ectotherms are tightly linked to ambient temperature.

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Hibernation in golden hamsters (Mesocricetus auratus, W.) exposed to 5% CO2

Abstract: Chronic exposure of golden hamsters to a gas mixture containing 5% CO2, 21% O2, and 74% N2 favors entry into hibernation. In the hibernating golden hamster, however, chronic CO2 exposure facilitates arousal.

Cited by 8 publications

References 5 publications

Cardiorespiratory and metabolic reactions during entrance into torpor in dormice, Glis glis

Cardiorespiratory and metabolic reactions during entrance into torpor in dormice, Glis glis

Mammalian Hibernation: An Escape from the Cold

Hibernation and Gas Exchange

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